Show:
Elements
Matter
Bonding
Water Properties
pH
100
The atomic number of an element represents...
What is the atom's number of protons.
100
The three phases of matter are...
What is solid, liquid and gas.
100
An ionic bond is defined by __________, while a covalent bond is defined by _________.
What is transfer of electrons between a non-metal and metal; sharing electrons between two non-metals.
100
Water is a polar molecule because...
What is oxygen is a highly electronegative atom, which means it has a high affinity for electrons. Electrons in the O-H bonds in water are pulled towards the oxygen pole of the molecule, creating a polar covalent bond.
100
A pH scale measures...
What is the acidity or basicity of substances.
200
An element is...
What is a pure substance that cannot be broken down into other substances.
200
Make up 96% of living biomass.
What is oxygen, hydrogen, nitrogen and carbon.
200
Arrange the following types of bonds in order of strength from strongest to weakest: hydrogen bonds, covalent bonds, ionic bonds.
What ionic bond > covalent bond > hydrogen bond.
200
Cohesion is __________, while adhesion is __________.
What is the tendency for like molecules to stick together; the tendency for unlike molecules to stick together.
200
An acid ________ H+ when dissolved in water, while a base ________ H+ when dissolved in water.
What is donates, accepts.
300
To find the number of neutrons in an element you...
What is subtract the atomic number from the atomic mass.
300
A(n) __________ reaction absorbs more energy than it releases, while a(n) _________ reaction releases more energy than it absorbs.
What is endothermic (ice melting), exothermic (combustion).
300
A double bond is ________ and ________ than a single bond.
What is shorter and stronger.
300
Ice floats because...
What is water molecules in ice are spaced farther apart from one another than in liquid, forming a crystal lattice structure. This results in less dense packing of water molecules in ice than in liquid water. Thus, the less dense ice floats.
300
The ______ the pH of a substance, the ________ the number of H+.
What is a) lower, higher (acid) b) higher, lower (base)
400
Describe the structure of an atom in detail.
What is protons (+) and neutrons (0) in the central compact nucleus; electrons (-) orbit the nucleus in electron shells of different energy levels.
400
A compound is ___________, while a molecule is ___________.
What is a substance containing two or more elements; a substance containing multiple atoms, either or same or different elements. All compounds are molecules, but not all molecules are compounds.
400
When drawing a Lewis Dot structure for an ionic substance, we indicate where ionic bonds form by...
What is circling the electron(s) being transferred and drawing an arrow to their final destination.
400
Water heats up slower than metal due to a higher _________. Energy must first be used to __________ before water's temperature increases.
What is specific heat capacity; break hydrogen bonds.
400
A substance with a pH of 4 would have _________ times ______ H+ ions than a substance with a pH of 7.
What is 1,000 more.
500
Electrons don't smack into one another because __________ and don't fly out of orbit because _________.
What is the negative subatomic particles repel one another and are attracted to the positively charged protons in the central nucleus.
500
What you get when you change the number of 1) protons 2) neutrons 3) electrons in an element.
What is 1) a different element 2) an isotope of the same element 3) an ion of the same element.
500
A subscript in a chemical formula indicates...
What is the number of atoms of that type of element.
500
The atoms on a molecule are considered only partially charged because...
What is there is no full transfer of electrons to the oxygen atom. The electrons in the O-H bond in a water molecule simply spend more time near the oxygen pole of the molecule, creating a polarized covalent bond.
500
A ________ is a substance that allows a solution to resist changes in ______.
What is buffer, pH.